LT1078/LT1079
APPLICATIONS INFORMATION
Matching Specifications
In many applications the performance of a system de-
pends on the matching between two op amps, rather than
the individual characteristics of the two devices. The two
and three op amp instrumentation amplifier configura-
tions shown in this data sheet are examples. Matching
characteristics are not 100% tested on the LT1078/LT1079.
Table 1
PARAMETER
V
OS
Match,
∆V
OS
LT1078AC/LT1079AC/LT1078AM/LT1079AM
50% YIELD
98% YIELD
30
110
40
150
0.5
1.2
6
8
0.12
0.4
120
100
117
105
LT1078C/LT1079C/LT1078M/LT1079M
50% YIELD
98% YIELD
50
190
50
250
0.6
1.8
6
10
0.15
0.5
117
97
117
102
UNITS
µV
µV
µV/°C
nA
nA
dB
dB
LT1078
LT1079
Temperature Coefficient
∆V
OS
Average Noninverting I
B
Match of Noninverting I
B
CMRR Match
PSRR Match
Comparator Applications
The single supply operation of the LT1078/LT1079 and its
ability to swing close to ground while sinking current
lends itself to use as a precision comparator with TTL
compatible output.
4
OUTPUT (V)
OUTPUT (V)
INPUT (mV)
V
S
= 5V, 0V
200µs/DIV
LT2078/79 • F03
2
0
INPUT (mV)
0
–100
Figure 3. Comparator Rise Response
Time to 10mV, 5mV, 2mV Overdrives
12
U
W
U
U
Some specifications are guaranteed by definition. For
example, 70µV maximum offset voltage implies that mis-
match cannot be more than 140µV. 97dB (= 14µV/V)
CMRR means that worst-case CMRR match is 91dB
(= 28µV/V). However, Table 1 can be used to estimate the
expected matching performance at V
S
= 5V, 0V between
the two sides of the LT1078, and between amplifiers A and
D, and between amplifiers B and C of the LT1079.
4
2
0
100
0
V
S
= 5V, 0V
200µs/DIV
LT2078/79 • F04
Figure 4. Comparator Fall Response
Time to 10mV, 5mV, 2mV Overdrives
LINER [ LINEAR TECHNOLOGY ]
